Shimano SLX 4-piston brakes offer familiar feel and similar power at a better price [Review]
If the amount of brake options on the market isn’t enough, the lines between each brand’s brakes can still be overwhelming. Within Shimano’s range of MTB brakes, the most common options are of course SLX, XT and XTR. Shimano’s XTs have earned a reputation as mid/high quality brakes. 4-piston options are powerful enough for trail and gravity riding, reliable and easy to bleed.
Having spent a lot of time riding Shimano XTs on several different review bikes over the past few years – it seems the majority of bikes I’ve seen include XT brakes versus SLX – I was curious to know how the Shimano SLX 4-piston brakes felt.
Shimano was kind enough to send out a set last fall. They didn’t have rotors on hand, so I used a Magura rotor and one from Galfer and put the SLX brakes on the easy-to-kit Privateer 161 which is a heavy enduro bike with a knack for speed. With external cable routing, I had one less thing to worry about during installation and after cutting the hoses and plugging them into the master cylinders, the SLX brakes were ready for action.
Before we get into brake performance, we’ll dive into what SLX brakes are and how they differ from XT and XTR.
About Shimano SLX 4-piston brakes
Like the XT and XTR brakes, the SLX’s stopping power has been increased by 10% and piston retraction has been improved. The SLX brakes (445g per brake) weigh about 70g more per set than XTR and 35g per set more than XT. All three use a combination of 15mm and 17mm pistons, with the larger piston driving the caliper, and there is a banjo bolt to adjust the direction of the brake line.
Where does the extra weight come from? Shimano told us “The weight difference comes almost entirely from the recommended rotor pairing.” Shimano’s published weight specifications for complete brakes are based on “Average weight (g) (kit for 800mm front, with recommended 160mm disc brake rotor, with lock ring, without adapter, with 2 bolts, with buffer resin) Recommended rotor for XT brakes is RT-MT800 while recommended rotor for SLX is SM-RT70 Calipers are the same weight SLX levers are 2g heavier as they have a stopper in place of the free travel screw.
Often the difference between high-end components like the XT and XTR and others like the SLX is weight and finish, and the finish is clearly different on the SLX. The XT is a pretty minor upgrade with a brighter feel, and for some that might be worth it. The XTR has a polished aluminum look that clearly hints at a higher price.
Like the XT and XTR, the SLX brakes are available in a 2 and 4 piston configuration and they all accept either finned or non-finned brake pads. The brake set we received came with a set of finned metal pads.
On the master cylinders and levers, the SLX retains much of what makes the XT and XTR great: an ergonomic lever blade, tool-less lever reach adjustment, clamshell handlebar mount, and Servo Wave. . Servo Wave is a feature that speeds up the action in the lever at the start of the stroke to quickly engage the pads with the rotor, and saves more space at the lever for modulation and bite power on the rotor.
The SLX levers have a smooth rather than dimpled lever blade and do not have an adjustable free-travel adjuster that would allow users to adjust the bite point on the brakes. But not everyone is sold on how this actually works. The Shimano SLX brakes have an MSRP of $186.99 per set, excluding rotors.
On the track
Installation was quick and easy, especially on an outboard routed chassis. Front and rear brake lines are 1000 and 1700mm long. On a long enduro bike, there was adequate line available. I lost some fluid during the initial cut and install and decided to skip a bleed back then to see how they performed. As mentioned, I have configured them with 200mm Galfer and Magura rotors with no problem.
Tool-less reach adjusts for accelerated setup time and the levers are as familiar as any other Shimano lever. Aside from the slick lever blade, my hands can’t tell the difference between SLX and XT. Some levers and masters out there feel and look ginormous, and I appreciate the shorter blade and smaller body of the Shimano brakes.
The SLX braking action resembles that of the XT and XTR. The action is light and you can feel the pads engage halfway through the stroke. There is a distinct bite point and room in the throw to apply more power. The amount of power is similar to the TRP Slate Evos I’ve used on another bike and the price is also similar. I was surprised to see the SLX brakes weigh about 130g more per set than the Shimanos because the TRP is a heavy brake.
So they’re not the strongest, most powerful brakes on the market, like the TRP DHR Evos or Shimano’s long-running Saint downhill brakes. Fatigue can build up in the hands and forearms on long descents and there are times when I would just like a little more clamping force, but in most cases the SLX brakes were enough, also noting that they are ridden on a heavy long-travel bike that rolls faster than a shorter-travel bike and is taken on trails where downhill is the priority.
After a few months, I gave the brakes a quick lever bleed that took about 10 minutes and swapped out a few air pockets for fresh mineral oil. This produced a noticeable improvement in potency. Seamless bleeds always remind me why I love Shimano brakes.
Around the same time, I added some Miles Wide Rough Riders to the lever blades. They’re small stickers with a gritty, tape-like surface, although they’re not really sandpaper, so they’re easier on your gloves. At $8, it’s a pretty smart little upgrade and you don’t feel like you’re missing out on anything between the nicer Shimano levers.
My wife ordered a brand new bike a few months ago and after a run down I asked her how it felt. She replied “good, but it sounds like there is noise coming from somewhere”. It’s probably your brake pads, I told him, since the bike came with XTs and finned pads. “I have the same rattle,” I said. It wasn’t a big problem for me. There are tricks to quieting pad noise, but I’ll probably try a set of finless pads when I have to buy a new one.
Overall, the SLX brakes proved to be a valid and more affordable option than the XT and XTR. I was primarily curious to see if the more affordable option could still match the power of top-shelf brakes with the acceptable concessions of extra weight and the loss of a few other features. The 4-piston SLX brakes have proven themselves as competitors, especially with the XTs selling for $40-50 per set more than the SLX.
If you’ve gone with the Shimano brakes but are wondering if you need the flash or the extra features on XT or XTR, the Shimano SLX 4-piston brakes are a great option. They’re heavier in the hand but lighter on the wallet and feel almost the same as the more expensive options.
- Same power as XT/XTR for a better price
- The concessions in features are worth the price
Advantages and disadvantages of Shimano SLX (BR-M7120) 4-piston brake
- Heavier than other brakes at a similar price
- Competitive options at this price